§4 · Agent 4 · Sheaf–function dictionary · 2026-10-17T02:40:19Z

Dead end 4.10 · \(\GL_6/\Sp_6\) at the label \((1,1,1,1,0,0)\): the three in-box translates do not suffice; a larger box is needed

blocked audit: error

Error. Four of the twelve displayed values are false (proved in Correction 10.7; recomputed by enumeration of t-stable Lagrangians for q = 3, 5, 7, e.g. q = 3: R2 = (120, 4320, 16, 0), R3 = (1080, 0, 24, 1) instead of (40, 480, 16, 0) and (40, 0, 0, 1)). Correct values: R2 = (q(q+1)(q²+1), q³(q+1)²(q²+1), (q+1)², 0), R3 = (q³(q+1)(q²+1), 0, q(q²−1), 1); R1 is right. In particular R3 is nonzero at c3, so step 1's 'the c3-entry forces b = 0' is false as stated. The conclusion e2 ∉ span(R1,R2,R3) still holds (the c4-entry gives c = 0 first, then c3 gives b = 0, then c1 gives a = 0), and so do the blocked status and 'a larger box is needed'. The values are labelled 'not machine-checked; heuristic', but they are definite counts and four are wrong. Beyond the node: one translate from the larger box, of type (0,0,0,0,0,−2), equals q(q+1)·1_{O_{c1}} and with R1 gives 1_{O_{μ2}} (Correction 10.7); the run's later theorem Theorem 5.7 proves (SG) for all GL2m/Sp2m over every F. The conclusion still holds by another argument.
Corrected by: Correction 10.7 · Correction: the in-box Hecke translates of \(\GL_6/\Sp_6\) at \(\sum\mu=4\), and one translate that reaches \((1,1,1,1,0,0)\), Correction X1.3 · GL₆/Sp₆ at Σμ=4: the twelve values of R1–R3, e₂∉span, one larger-box translate.

The method of the \(\GL_4/\Sp_4\) case is tried at the uncovered label \(\mu_2=(1,1,1,1,0,0)\) of \(\GL_6/\Sp_6\): the three Hecke translates by lattices between \(t\cO^6\) and \(t^{-1}\cO^6\) do not produce \(\one_{O_{\mu_2}}\), so deciding (SG) there needs translates by lattice types with entries \(\pm2\). The route stops here.

Dead end 4.10.

Let \(X=\GL_6/\Sp_6\) and \(\mu_2=(1,1,1,1,0,0)\), an uncovered label with \(\sum\mu=4\) whose lower set is \(\{\mu_2\}\). The orbits with \(\sum\mu=4\) met by translates by lattices in the box \(t\cO^6\subseteq M\subseteq t^{-1}\cO^6\) are $$c_1=(2,2,0,0,0,0),\qquad c_2=\mu_2,\qquad c_3=(2,2,1,1,-1,-1),\qquad c_4=(2,2,2,2,-2,-2),$$ and the lattice types in the box with \(\sum\nu=-2\) are \(R_1:(0,0,0,0,-1,-1)\), \(R_2:(1,0,0,-1,-1,-1)\), \(R_3:(1,1,-1,-1,-1,-1)\). By hand counts as in Theorem 4.9 (not machine-checked; heuristic), the translates take the values, on \((c_1,c_2,c_3,c_4)\), $$R_1=\big(1,\ (q+1)(q^2+1),\ 0,\ 0\big),\qquad R_2=\Big(\tfrac{q^4-1}{q-1},\ (q+1)(q^2+1)(q^2+q),\ (q+1)^2,\ 0\Big),\qquad R_3=\big((q+1)(q^2+1),\ 0,\ 0,\ 1\big).$$ Consequently \(e_2=\one_{O_{\mu_2}}\notin\operatorname{span}(R_1,R_2,R_3)\).

Blocked. Deciding (SG) at \(\mu_2\) needs translates by lattice types with entries \(\pm2\). Missing lemma: the finite linear-algebra statement "\(\one_{O_\mu}\in\cH_K\varphi_0\) for the uncovered \(\mu\) of \(\GL_{2m}/\Sp_{2m}\) (\(m\ge3\)), \(\SL_{2n}/\Sp_{2n}\) (\(n\ge3\)) and \(E_6/F_4\) over \(\F_q(\!(t)\!)\)".

  1. Linear algebra. If \(e_2=aR_1+bR_2+cR_3\), the \(c_3\)-entry forces \(b=0\), the \(c_4\)-entry forces \(c=0\), and \(R_1\) alone is not proportional to \(e_2\).
  2. What would be needed. Translates by lattice types with entries \(\pm2\), i.e. lattices in the box \(t^2\cO^6\subseteq M\subseteq t^{-2}\cO^6\), where new columns \((3,3,\dots)\) appear. That enumeration, of the order of \(q^{18}\) Hermite forms, was not run.
  3. Two ways to supply the missing lemma. Either a larger lattice count, or a transfer of Theorem E / Proposition F to \(\F_q(\!(t)\!)\) (Objection 4.12). With the lemma, Theorem 4.6 would decide those sheaf rows.

Builds on

  • Theorem 4.9 · \(\GL_4/\Sp_4\): the uncovered label \((1,1,1,1)\) is reached by Hecke translates, so (SG) holds over \(\F_q(\!(t)\!)\) and \(\Csat=\cC_K\)

Built on by

Original record, as the agent wrote it at 02:40 UTC

GL6/Sp6 label (1,1,1,1,0,0): the three in-box translates do not suffice; larger box needed

Same method for \(X=\mathrm{GL}_6/\mathrm{Sp}_6\), uncovered label \(\mu_2=(1,1,1,1,0,0)\) (\(\sum\mu=4\)); its lower set is \(\{\mu_2\}\) alone. Orbits with \(\sum\mu=4\) meeting translates by lattices in the box \(t\mathcal O^6\subseteq M\subseteq t^{-1}\mathcal O^6\): \(c_1=(2,2,0,0,0,0)\), \(c_2=\mu_2\), \(c_3=(2,2,1,1,-1,-1)\), \(c_4=(2,2,2,2,-2,-2)\). Lattice types in the box with \(\sum\nu=-2\): \(R_1:(0,0,0,0,-1,-1)\), \(R_2:(1,0,0,-1,-1,-1)\), \(R_3:(1,1,-1,-1,-1,-1)\). By the same hand counts as A4-9.1 (not machine-checked; heuristic): $$R_1=(1,\ (q+1)(q^2+1),\ 0,\ 0),\quad R_2=\Big(\tfrac{q^4-1}{q-1},\ (q+1)(q^2+1)(q^2+q),\ (q+1)^2,\ 0\Big),\quad R_3=((q+1)(q^2+1),\ 0,\ 0,\ 1).$$ \(e_2\notin\operatorname{span}(R_1,R_2,R_3)\): the \(c_3\)-entry forces the \(R_2\)-coefficient to vanish, the \(c_4\)-entry forces the \(R_3\)-coefficient to vanish, and \(R_1\) alone is not proportional to \(e_2\). So deciding (SG) at \(\mu_2\) needs translates by lattice types with entries \(\pm2\) (box \(t^2\mathcal O^6\subseteq M\subseteq t^{-2}\mathcal O^6\)), where new columns \((3,3,\dots)\) appear; the enumeration (\(\sim q^{18}\) Hermite forms) was not run. Blocked: missing lemma = the finite linear-algebra statement "\(\mathbf 1_{O_{\mu}}\in\mathcal H_K\varphi_0\) for the uncovered \(\mu\) of \(\mathrm{GL}_{2m}/\mathrm{Sp}_{2m}\) (\(m\ge3\)), \(\mathrm{SL}_{2n}/\mathrm{Sp}_{2n}\) (\(n\ge3\)), \(E_6/F_4\) over \(\mathbb F_q(\!(t)\!)\)", either by a larger lattice count or by transferring Theorem E / Proposition F to \(\mathbb F_q(\!(t)\!)\) (A4-12). With it, Theorem A4-6 would decide those sheaf rows.

Sources